Improvement in the art of tanning



UNITED STATES PATENT OEErcE.

ROBERT, HEIN, OF ST. MARYS, PENNSYLVANIA.

IMPROVEMENT IN THE ART OF TANNING.

Specification forming part of Letters Patent No. 194,090., dated August14, 1877 application filed April 30, 1877.

To all whom it may concern:

Be it known that I, ROBERT HEIN, of St. Marys, in the county of Elk andState of Pennsylvania, have invented a certain new and useful Bate orCompound for Tanning Purposes; and I do hereby declare that thefollowing is a full, clear, and exact description thereof.

This invention relates to that class of com pounds used in the tanningof leather or skins. It is What is known in the trade as a hate, and isused to take out the lime and open the pores of the skins.

The compound consists of equal parts of red arsenic and potash, withsufficient warm water to dissolve them.

The potash is dissolved first in the warm water, then brought to aboiling-point, when the arsenic is added.

In using the bate the compound is put'in the vat, and sufficient wateradded to cover the hides.

For, say, three hundred calf-skins the pro portions will be about twopounds of red ar' senic and two pounds of potash, with water as above;for, say, one hundred upper sides, the same; for, say, one hundred kip,about three pounds of red arsenic and three pounds of potash.

The compound is put in the Vat with the hides as warm as the safety ofthe hides will allow, and they are left in it for four or five hours,having been handled at least every half hour during the bath, when theyare removed and put in the liquor the same as usual,

This bate does not injure the leather, which retains its usual weightand color, but it does take the lime out of the hides in one-third ofthe time now required; also, saves at least one-third of the bark andlabor required by the common process. It is also much superior to anybate now in use for opening the pores of the skins.

I am aware that a preparation of arsenic has been used in tanning, butnot during that part of the process for which my bate is used.

I therefore claim- As an improvement in the art of tanning, a hatecomposed of red arsenic, potash, and water, prepared as described, andfor the purpose set forth.

Witnesses:

DAVID R. SEooR, J. M. MEoUM.

ROBERT HEIN.

